Compositions containing poly(phenylene ether)s and styrenic block copolymers are known and valued for their improved properties relative to either resin type alone. For example, U.S. Pat. No. 3,660,531 to Lauchlan et al. describes blends of “polyphenylene oxide resin” with styrene-butadiene block copolymers and teaches that the blends exhibit a useful combination of low-temperature melt processability, high impact strength, and high flexural strength. As another example, U.S. Pat. No. 5,234,994 to Shiraki et al. describes blends of a “polyphenylene ether”, a polystyrene, and a block copolymer of a vinyl aromatic hydrocarbon and a conjugated diene. The blends are described as offering improved transparency, impact resistance, surface hardness, heat resistance, and gloss. As yet another example, U.S. Pat. No. 6,274,670 to Adedeji et al. describes blends of a “polyphenylene ether resin”, a non-elastomeric styrenic resin, and an unsaturated elastomeric styrenic block copolymer. When the non-elastomeric styrenic resin is a styrene-butadiene block copolymer having at least 50 weight percent styrene, the compositions are semi-transparent and exhibit enhanced processability.
Despite these advances, poly(phenylene ether) compositions with high light transmittance, low haze, and high impact-resistance remain an elusive target. Although the use of optical enhancing agents and flame retardants can improve light transmittance and reduce haze, they also reduce impact strength. There is therefore a need in the packaging and healthcare industries, among others, for poly(phenylene ether) compositions that exhibit an improved balance of high light transmittance, low haze, and high impact strength.